In recent years, a fuel cell vehicle (FCV) has been developed. The FCV has a fuel cell to cause a chemical reaction of hydrogen and oxygen so as to generate electric energy. The FCV consumes the generated electric energy to activate a motor to obtain driving force of the vehicle. The FCV is connected with a feed pipe in a hydrogen station, and a hydrogen tank of the FCV is supplied with hydrogen (fuel) through the feed pipe (see US Patent 20020014277, JPA-2001-355795). The following methods (1), (2) for charging hydrogen may be conceived.
(1) Charging of hydrogen while a charging pressure of hydrogen is maintained at a low pressure such that a temperature in a hydrogen tank does not increase.
(2) Setting of the charging pressure of hydrogen at a high pressure in the beginning of hydrogen charge. Monitoring of the temperature in the hydrogen tank during the hydrogen charge, and decreasing the charging pressure or temporarily stopping the hydrogen charge when the monitored temperature becomes high.
In the method (1), hydrogen charge takes long, since the charging pressure is low. In the method (2), hydrogen charge cannot be efficiently performed, since the charging pressure is controlled subsequent to detection of temperature change in the hydrogen tank.